Vertical grain-drying device

ABSTRACT

A grain-drying device is constituted by a plurality of horizontal layers which are vertically juxtaposed and respectively formed of inverted truncated pyramid sections adjacent one another and with common upper bounding edges to define a honeycomb arrangement, the sections of each layer being horizontally offset from the sections of the next lower layer such that apertures in the lower ends of the sections of the upper layer are disposed at the junctions of the sections of the lower layer whereby downwardly flowing material in each section will divide and pass into the adjoining sections in the lower layer. The downwardly flowing material is dried by passing a drying medium through broken channels formed between adjacent sections in each layer.

United States Patent 2,386,670 10/1945 Evans lnventors Nikola Beograd lvackovic;

Milija Urosevic, Cacak, Yugoslavia Appl. No. 867,236

Filed Oct. 17, 1969 Patented May 25, 1971 Assignee Cer Preduzece Termo-Tehnickih Uredajaja l Montaza Cacak, Yugoslavia VERTICAL GRAIN-DRYING DEVICE 2,656,007 10/1953 Arnoldetal 3,199,215 8/1965 Jesseetal ABSTRACT: A grain-drying device is constituted by a plurality of horizontal layers which are vertically juxtaposed and respectively formed of inverted truncated pyramid sections adjacent one another and with common upper bounding edges to define a honeycomb arrangement, the sections of each layer being horizontally offset from the sections of the next lower layer such that apertures in the lower ends of the sections of the upper layer are disposed at the junctions of the sections of the lower layer whereby downwardly flowing material in each section will divide and pass into the adjoining sections in the lower layer. The downwardly flowing material is dried by passing a drying medium through broken channels formed between adjacent sections in each layer.

VERTICAL GRAIN-DRYING DEVICE BRIEF SUMMARY OF THE INVENTION The invention relates to a grain-drying device.

There are various known types of drying devices for grain (e.g. corn, wheat, rice, etc.), but such devices have the disadvantage of nonunifonn grain drying while requiring large heat consumption.

An object of the invention is to provide a grain dryer which will provide rapid and uniform grain drying with relatively modest heat requirements.

According to the invention there is provided a grain drying device employing drying cells in the pattern of hexagonal truncated pyramids welded together to form layers which are stacked one on the other to form a honeycomb in which the grain passes from the cells of one layer to those-in the next layer through apertures at the bottom of the cells, while a drying medium is passed through passages of triangular cross section between adjacent cells.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a portion of a honeycomb layer of a grain-drying device, one cell of said portion being shown in heavy outline;

FIG. 2 is a plan view showing one cell of a layer with three adjoining cells in the next lower layer;

FIG. 3 is a cross-sectional view taken on line A-A in FIG. 2; and

FIG. 4 is a plan view illustrating the path of travel of the drying medium through the device.

DETAILED DESCRIPTION A grain-drying device is provided with a plurality of horizontal layers 1 which are vertically juxtaposed in a stacked arrangement in a tower (not shown) to form a honeycomb arrangement. The layers 1 control both the downward flow of grain to be dried and the flow of the drying medium in a manner which will become evident later.

Each layer 1 is constituted by a plurality of adjacent sections or cells 2, each in the shape of an inverted truncated, hexagonal pyramid. The cells are made of a sheet metal material and the sides of the cells 2 are inclined at an angle of 45 with respect to'the horizontal, as shown in FIG. 3. Adjacent cells have common upper edges 5 which are welded or otherwise secured together whereby each layer is formed as a unitary body. At the lower end of each cell 2 there are provided apertures through which the grain passes to the cells of the next lower edge. Adjacent layers are offset horizontally by a distance equal to the length of an upper edge of a cell whereby each aperture is positioned at the junction 3 of three adjoining cells, as shown in FIG. 2. The apertures are in the form of notches 7, which are three in number (one for each lower cell), and with solid projection portions 6 between adjacent notches'The projection portions 6 of the cells of one layer rest on the upper edges of the cells of the next lower layer as shown in FIGS. 2 and 3. The grain in the cells 2 passes, by gravity, through the notches 7 into respective lower cells and then the grain in each cell is dividedin its downward passage through the layers, whereas each cell collects grain at three-comers at its upper edge from three overlying cells. With such a distribution system, the grain is constrained to flow so as to ensure complete mixing of the grain mass introduced into the tower. The grain is dried by contact with a drying medium as it passes through the tower, as will be explained later, and before the grain is discharged from the tower it passes through a cooling zone at the lower end thereof.

The honeycomb arrangement of the layers in the tower constrains each single grain in its passage through the drying and cooling zone, to follow a very complex trajectory, which may be made up of many irregular geometrical forms, which may not be equal for every single grain, thus provoking the grain mass during its movement to be exposed to be a very complex mixing in all directions of the lateral and longitudinal cross section of the drying tower. This represents a prime purpose of this invention.

The inclination at 45 of the sidewalls of each honeycomb cell 2 causes a steady sliding of the grain during its movement, eliminating any possibility of grain stoppage on any layer within the honeycomb system.

The honeycomb arrangement provides in each layer 1 passageways for the circulation of a drying medium (generally heated air), said passageways being constituted by channels 4 of isosceles triangular cross section which extend in nonlinear, broken arrangement throughout the layers. As seen in FIG. 4, the drying medium is introduced into the honeycomb tower laterally, at various levels, in the direction indicated by reference numeral 8 through channels 4. The drying medium traverses the channels 4 and divides itself and combines as illustrated. It is to be noted that the drying medium introduced in each channel 4 at one side of the tower travels along a zigzag branch extending in the inlet direction 8, whereas at each junction 3, the medium divides as shown at 9 and branches transversely at 30 angles for transverse discharge while also forming further zigzag branches 10 in the direction 8. Ultimately, the medium is discharged from the sides of the tower other than the one through which the medium was introduced.

The medium may be introduced at different sides of the tower at different levels to promote the intensity of drying.

At various junctions 3, the drying medium admitted through different channels 4 along one side of the tower can intermix and circulate.

The flow of the drying medium above the grain mass surface in the honeycomb is conducted with a relatively great velocity (approximately 6 meters per second), with all characteristics of turbulent streaming, thus principally differing from hitherto known arrangements in which a low velocity of drying medium is obtainedthrough the layers of grain (approximately 0.3 meters'per second) having the characteristics of laminar flow with imminent formation of a boundary layer on the grain surface.

According to the invention, the controlled air movement toward the grain mass within the honeycomb system enables a more intensive heat and moisture exchange compared with the hitherto known systems, causing the grain to be discharged at a lower temperature under the same conditions.

lclaim:

1. A vertical grain-drying device comprising a plurality of horizontal layers which are vertically juxtaposed and define a honeycomb arrangement adapted for the downward flow of material to be dried, each layerincluding inverted truncated pyramid sections adjacent one another and with common upper bounding edges, each section having a lower end with an aperture disposed at the junction of a plurality of lower sections whereby material flowingdownwardly in such section will pass into the lower sections at said junction, adjacent sections in the same layer defining channels of triangular cross section for the passage therethrough of a drying medium to dry the downwardly flowing material.

2. A device as claimed in claim 1, wherein said aperture at the lower end of each section is constituted by a plurality of notches, one for each section at the junction therebelow, each section having solid projecting portions between adjacent notches.

3. A device as claimed .in claim I, wherein each layer is constituted of bent sheet material.

4. A device as claimed in claim 3, wherein the sections of each layer are joined along the common upper bounding edges.

5. A device as claimed in claim 4,. wherein said sections are welded along said common upper bounding edges.

6. A device as claimed in claim 1, wherein said sections are hexagonal.

7. A device as claimed in claim 6, wherein said sections have walls inclined at an-angle of 45 with respect to the horizontal, the sections in adjacent layers being offset horizontally by a distance equal to the length of one side of a section 9. A device as claimed in claim 2, wherein the projecting at the upper edge thereof. portions of the sections of one layer rest on the upper edges of 8. A device as claimed in claim 1 wherein said channels the sections of the next lower layer, whereby one layer is supdefine a nonlinear passage for the drying medium. ported on another. 

1. A vertical grain-drying device comprising a plurality of horizontal layers which are vertically juxtaposed and define a honeycomb arrangement adapted for the downward flow of material to be dried, each layer including inverted truncated pyramid sections adjacent one another and with common upper bounding edges, each section having a lower end with an aperture disposed at the junction of a plurality of lower sections whereby material flowing dowNwardly in such section will pass into the lower sections at said junction, adjacent sections in the same layer defining channels of triangular cross section for the passage therethrough of a drying medium to dry the downwardly flowing material.
 2. A device as claimed in claim 1, wherein said aperture at the lower end of each section is constituted by a plurality of notches, one for each section at the junction therebelow, each section having solid projecting portions between adjacent notches.
 3. A device as claimed in claim 1, wherein each layer is constituted of bent sheet material.
 4. A device as claimed in claim 3, wherein the sections of each layer are joined along the common upper bounding edges.
 5. A device as claimed in claim 4, wherein said sections are welded along said common upper bounding edges.
 6. A device as claimed in claim 1, wherein said sections are hexagonal.
 7. A device as claimed in claim 6, wherein said sections have walls inclined at an angle of 45* with respect to the horizontal, the sections in adjacent layers being offset horizontally by a distance equal to the length of one side of a section at the upper edge thereof.
 8. A device as claimed in claim 1, wherein said channels define a nonlinear passage for the drying medium.
 9. A device as claimed in claim 2, wherein the projecting portions of the sections of one layer rest on the upper edges of the sections of the next lower layer, whereby one layer is supported on another. 